Marine engine exhaust unit



FIG. 1 is a perspective view of a marine engine exhaust unit showing my new design;

FIG. 2 is a top plan view thereof on a reduced scale;

FIG. 3 is a bottom plan view thereof on a reduced scale;

FIG. 4 is a right end elevation view thereof;

FIG. 5 is a front elevation view thereof on a reduced scale; and

FIG. 6 is a rear elevation view thereof on a reduced scale. 

The ornamental design for a marine engine exhaust unit, as shown. 